Self-centering transfer punch



NOV. 18, 1958 J, J, SMH-H SELF-CENTERING TRANSFER PUNCH Filed July 26,1955 ATTD RN EYS p as at 27 for engagement with United States l PatentOtlice 2,860,421 -SELF-CENTERING TRANSFER PUNCH Joseph J. Smith, EastHartford, Conn. .Application July 26, 1955, Serial No. 524,391 3 Claims.(Cl. 33-191) and more particularly centering transfer punch whichinexpensive to manufacture.

Other objects and advantages Will be apparent during the course of thefollowing description.

In the accompanying drawings, forming a part of this application, and inwhich like numerals are used to designate like parts throughout thesame:

Figure l is an elevational View of the transfer punch, constructedaccording to the present invention.

Figure 2 is a sectional view taken on the line 2 2 of Figure 1 andillustrating the punch in use.

Figure 3 is an elevational View showing the punch removed from thesupport and body members.

Figure 4 is an elevational view illustrating the body member.

Figure 5 is a bottom plan view of the device.

Figure 6 is a longitudinal sectional view taken through the supportmember.

Figure 7 is atop plan view of the device.

Referring in detail to the drawings, there is shown a self-centeringtransfer punch which includes a body member 10, a cylindrical punch 11,and a support member 12.

The body member 10 may be made of any suitable material such as hardenedmetal, and the body member 10 includes an upper enlarged portion 14 thatmay be knurled exteriorly as at so as to facilitate the grippingthereof. The body member 10 further includes a reduced diameter portion16 and there is provided in the body member 10 a longitudinallyextending bore 17. There is provided on the reduced diameter portion 16a threaded section 19 for a purpose to be later described, and the loweredge of the reduced diameter portion 16 is tapered or beveled as at 18,Figure 4.

The punch 11 extends through the bore 17 in the body member il), and thepunch 11 includes a major cylindrical portion 2t) which has a lowerpointed end 21. The pointed end 2l of the punch 11 is adapted to engageor form an indentation 22 in a work piece 23, and a template 24 having aplurality of openings 25 therein may be used in conjunction with thework piece 23.

The construction of the support member 12 is shown in detail in Figure6. Thus, the support member 12 includes an upper enlarged shoulder 26which is threaded interiorly the threaded section 19 of the body member10. The support member 12 further includes a lower enlarged annularcollar 28, and there is provided an intermediate section or portion 31.Arranged in the' collar 28 and in the intermediate section 31 is aplurality of spaced radially disposed slits or slots 29 for a purpose tobe later described. The inner portion of the collar 28 may be taperedfor engagement with the tapered sur face 18 of the body member 10. Theexterior surface of the shoulder 26 may be knurled as shown in Figure l.

From the foregoing, it is apparent that there has been provided aself-centering transfer punch and in use, with the parts arranged asshown in the drawings, the template 24 is arranged on the work piece 23.Then the lower portion or collar 28 of the support member 12 is arrangedin engagement with the desired opening or hole 25 in the template 24. Bymanuallygripping the knurled shoulder 26, the support member 12 can besection 19 of the body member 10 and also due to the provision of theslots 29, the effective diameter of the collar 28 can be varied so thatit can be made to snugly fit openings 25 of different diameters orsizes. The tapered surface 30 on the interior of the support member 12engages the tapered surface 18 on the bottom of the body member 10 so asto maintain the parts in their proper position.

with the collar 28 snugly in the work piece 23.

The present invention can cover a wide range of material stockthicknesses or different diameters. Also, the device can be used inestablishing a center mark or datum point on various sizes of holes.

As an example of how the present invention may be used, a tool maker orsheet metal worker may be provided with a master template that may haveas many as fifteen holes of several decimal sizes in various locationswhich range from approximately .250 inch in diameter up to and including.350 inch in diameter. The tool maker might be asked to take the mastertemplate with the various size holes in it and with the use of a sharppointed steel scriber, proceed to mark the outline of the various holesizes above mentioned, onto possibly twenty pieces of at plate sheetmetal for the purpose of proscribed separately from the above mentionedmaster template. Previously, no fast or accurate method has been devisedto pick up the positive center of the fifteen above mentioned varioussized holes that he has to locate and provide a center mark for thepurpose of drilling these holes to the certain diameters as provided inthe master template above mentioned and to'tolerances of .003 diameterof positive location. In the above mentioned example, the mechanic doingthe job would take the transfer punch of the present invention and screwthe support member 12 onto the body member 10. Then, the spring colletor collar 28 would be set down in one of the holes 25, the templatebeing on top of the material 23. Then, the punch 11 is inserted in thebore 17 and the top of the punch can be struck with a mallet or hammer.This will make a center mark or prick punch mark for a positive startingpoint for vthe mechanic to drill the hole to a desired diameter hole.Thus, there will be a very large amount of time saved in layout ntransferring holes. Previously, it was necessary to make up individualtransfer punches for each hole size required.

I claim:

l. In a self-centering transfer punch, a body member including anenlarged cylindrical portion, said body member including a reduceddiameter cylindrical portion hav- Patented Nov. 1s, 195sy ing an upperthreaded section, there being a longitudinally extending bore in saidbody member, the lower edge of said body member being tapered, a punchextending through said bore and having a lower pointed end, a supportmember arranged over the reduced diameter portion of said body memberand including an intermediate cylindrical section, an enlarged shoulderarranged in threaded engagement with the threaded section of the reduceddiameter portion of said body member, there being an annular collar onthe lower end of said support member, there being a plurality of spacedradially disposed slots in said collar and in the intermediate sectionof said support member, the inner portion of the support member adjacentthe collar being tapered for engagement with the tapered lower end ofsaid body member and the lower edge of said support member being concavein cross section.

2. The structure as dened in claim 1, wherein said shoulder and whereinthe enlarged cylindrical portion of said body member are knurledexteriorly. l

3. In a self-centering transfer punch, a body member including an upperenlarged cylindrical portion7 said body member including a reduceddiameter cylindrical portion having an upper threaded section, therebeing a longitudinally extending bore in said body member, the loweredge of said body member being tapered, a punch extending through saidbore and including a major cylindrical portion, a lower pointed end, asupport member arranged over the reduced diameter portion of said bodymember and including an intermediate cylindrical section, an upperenlarged shoulder having a threaded interior arranged in threadedengagement with the threaded section of the reduced diameter portion ofsaid body member, there being an annular enlarged collar on the lowerend of said support member, there being a plurality of spaced radiallyA' disposed slots in said collar and in the intermediate section of saidsupportl member, the exterior surface of said shoulder and the exteriorsurface of said enlarged cylin- .drical portion being knurled exteriorlyand the lower end of said support member adjacent the collar beingconcave in cross section, said support member including an innerlongitudinally extending passageway including a lower tapered surfacefor engagement with the tapered lower edge of said body member so as tomaintain the parts in their proper positions.

References Cited in the le of this patent UNITED STATES PATENTS 953,282Nash Mar. 29, 1910 1,259,335 Acton Mar. 12, 1918 2,255,361: -MuellerSept. 9, 1941 2,519,908 Howard Aug. 22, 1950 l FOREIGN PATENTS 6,816Great Britain Feb. 8, 1896, of 1895

